<!DOCTYPEhtml>
<html  xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <!-- 关键代码 -->
    <script th:src="@{/webjars/jquery/3.2.1/dist/jquery.min.js}"></script>
    <script th:src="@{/webjars/bootstrap/4.3.1/js/bootstrap.min.js}"></script>
    <link rel="stylesheet" th:href="@{/webjars/bootstrap/4.3.1/css/bootstrap.min.css}" />
    <link type="text/css" rel="stylesheet" th:href="@{/static/css/style.css}">
</head>
<body>
<img th:src="@{${fileName}}" alt="..." class="img-rounded">
</body>
</html>